principle objective of this lecture is to present on Digestive System of Rodents. In the rat, as in all tetrapods, there is a sharing of the anterior structures of the digestive and respiratory system. Their caecum and appendix are enlarged to store the cellulase producing bacteria. Food pass the alimentary canal twice – first as food and then as soft faeces. To enable the animals to absorb the products of bacterial breakdown and allow rodent to recover the nutrients initially lost with the faeces.